Devices known as extrusion dampers which employ elastic or plastic deformation of certain materials to absorb energy are well known. U.S. Pat. No. 3,833,093 describes a form of extrusion damper consisting of an energy absorber material confined between an elongate outer jacket which is typically a cylinder, and a shaft which moves longitudinally within the jacket. The absorber material is typically lead while the jacket and shaft are typically formed of steel. Opposite ends of the jacket and shaft are connected between two members in a structure which are expected to move relative to one another during an earthquake or other induced motion. A general discussion of these and related devices is given in "An Introduction to Seismic Isolation", R I Skinner, W H Robinson and G H McVerry, Wiley, 1993.
Lead is the preferred deformable energy absorbing material for several reasons. First it yields at a room temperature shear stress of around 10.5 MPa which is low compared with other metals and equivalent plastic materials. Second it restores its mechanical properties through recrystallisation and associated processes relatively rapidly following yield deformations, which provides outstanding resistance to work hardening under cyclic shear at ordinary temperatures. Third lead is readily available at the purity required to exhibit these properties.
In practice such dampers are individually designed to protect a particular structure against damage by damping certain motions imparted to it. Their behaviour is quite closely approximated by that of an ideal Coulomb damper in having a force-displacement hysteresis loop which is nearly rectangular and practically rate independent over a wide range of frequencies. Research into performance of these devices is ongoing.